Locking key for car brakes



Sept. 28, 19.37. w. J. MACK LOCKING KEY F OR CAR BRAKES Filed June 1, 1934 Patented Sept. 28, 1937 UNITED STATES A'H'ENT OFFIQE 9 Claims.

My invention relates to improvements in keys for railway brakes, such as are designed for looking brake shoes to brake heads.

This application is in part a continuation of application Serial No. 555,680, filed August 7, 1931, now issued .as Patent No. 1,969,087, and one of the objects of my invention is the production of a key capable of being used for locking any standard brake shoe to a standard brake head, or such as are so classified by Master Car Builders Association; the key being one which will most effectively and securely fasten brake shoes to brake heads without play between the two, regardless of the usable condition of such parts, also without possibility of the keys falling out in the event that the car to which they are applied being inverted, as is often required with certain types of freight cars which are completely inverted with portions of the track on which they stand when delivering coal or other bulk material therefrom, thus preventing the brake shoes from dropping from the brake heads.

Another object of my invention is the production of an improved locking key for brake shoes which possesses the quality of drawing the brake shoe in firm contact with the brake head regardless of the wear on either or both; the key being so constructed that it will automatically take upv the wear of either or both.

A further object is to provide a locking key of this type, which comprises two elongated members detachably connected together at corresponding ends; and according to one embodiment of my invention such members are preferably made of bands or strips of metal of different thicknesses detachably connected together so that either member may be replaced in the event of its becoming broken or worn or bent beyond a point where it will function properly, thus eliminating the expense of a complete key and at the 'same time a key is provided which has the proper rigidity in one member and the much desired flexibility or resiliency in the other.

With the above and other objects in View to appear hereinafter, the invention consists in the novel features of construction, and in the arrangement and combination of parts to be hereinafter described and more particularly pointed out in the subjoined claims.

In the drawing:

Fig. 1 is a side elevation of a standard brake head and brake shoe applied thereto by means of my improved locking key.

Fig. 2 is a central vertical section through a brake head and brake shoe, showing my improved key in side elevation and in position to firmly lock the brake shoe to the brake head.

Fig. 3 is a cross section taken on line 3-3, Fig. 1.

Fig. 4 is a cross section taken on line 4-4, Fig. 1.

Fig. 5 is an inner face view of a standard brake shoe.

Fig. 6 is a side elevation of my improved locking key.

Fig. 7 is a side elevation of the foundation or long member of the key.

Fig. 8 is a side elevation of the resilient or short member of the key.

Fig. 9 is a broken front elevation of the key.

Fig. 10 is an enlarged section of the key taken on line lU-IB, Fig. 9.

In railway brake constructions, as now com monly used, brake shoes are removably applied to brake heads supported from the truck or under-frame of a car by means of hangers; brakebeams being also employed and each provided with two brake heads alined with axle-connected wheels of the car. A well known form of hanger is shown in the drawing, and it comprises a U-shaped link or element, the transverse or bight member of which is passed through a transverse opening or recess in the brake head and'is retained in said opening or recess by the brake shoe and the key employed to secure or look the shoe to the head; all of which is standard as railway car equipment. My improved locking key is designed for use in connection with any of the various makes of brake appliances possessing such features.

Reference being now had to the drawing inv detail, the numeral 9 designates the brake head, provided with a transverse opening ID to receive the brake-beam (not shown). This opening, as shown, is somewhat rectangular, but may be otherwise shaped, since the cross-sectional formation 'of brake-beams are varied by different manufacturers. Brake heads of different manufacture do not vary in any essentials or in size; and

' while varying slightly in shape, all are provided with hanger openings or recesses, such as shown at H, for the reception of the cross member [2 of a hanger l3.

Centrally between its ends, the brake head is provided with connector lugs M which are spaced apart vertically and their opposing faces beveled inwardly. Other lugs l5 extend outwardly from the brake head at the top and bottom, and these are spaced apart transversely at each end of the head.

The brake shoe [6 has a retainer element l1, comprising two transversely-spaced connector lugs 18 connected by a strap or bar l9, which in itself is spaced from the inner convex face of the brake shoe, forming in effect a loop adapted to fit into the space between the lugs M on the brake head. The transversely-spaced connector lugs E8 of the brake shoe are tapered or beveled inwardly at the top and bottom so as to conform to the beveled opposing faces of the connector lugs 5 on the brake head. In a broader sense, the lugs l8 and. the strap or bar 89 may be considered a single connector lug having an opening therethrough.

The connector lugs 54 are provided with openings 20, which are in the same vertical plane and are intended to register or partly register with the space 2! between the convex surface of the brake shoe and the opposing surface of the strap or bar IS. The lugs 55 at each end of the brake head are adapted to receive between them lugs 22 arranged at the top and bottom of the brake shoe.

The description thus far relates to one manufacture of brake appliance approved by the Master Car Builders Association. My improved locking key is adapted for connecting or looking brake shoes to brake heads of this general type, although in many instances slight variations in form may exist.

My improved locking key, designated 23, like all keys employed for connecting brake shoes to brake heads, is inserted between the top and bottom lugs 22 of the brake shoe, passed through the openings 23 in the connector lugs arranged on the concaved face of the brake head between its ends, and through the space between the connector lugs E8 on the brake shoe.

The locking key comprises two members 24, 25, which are detachably connected together at their upper or corresponding ends, so that if either should become broken or worn while the other remains inserviceable condition, disconnection of these members can be easily made and the worn or broken part replaced with another while retaining the serviceable part. Member 24 of the locking key is somewhat shorter than member 25, and both members are curved lengthwise. The long member 25 I term a foundation member and at its upper end it is curved upon itself to provide a substantially circular loop 26. The short member I term a spring member for the reason that upon its resiliency dependency is had of the key being retained in position between the brake head and the brake shoe, and it also serves to take up any wear that may exist in either or both of these parts. Like the long or foundation member this short member is also provided at its upper end with a substantially circular loop 21, the outer diameter of which is approximately that of the inner diameter or loop 26 so that it can be thrust into said last-mentioned loop by sidewise movement and thus be retained therein by frictional contact. Since, however, these keys are shipped in bulk in large quantities and subjected to rough usage in transportation, as well as in stock rooms where they are stored until needed, I prefer to provide the loops 26 and 2? with interlocking means to guard against separation of the two parts of the key, when not in use, and to this end the large loop 26 is provided with an oval or other internal depression 26 to form an external teat or protuberance 26 thereon, and the small loop 2'! is similarly provided with a teat or protuberance 21* which is entered into the depression 2% of the loop 26. Thus regardless of accidental strain applied transversely to either of the loops, separation of the two key-parts cannot take place. The teats or protuberances need not be large, as any degree of projection on the loops will suffice and if too large would necessitate the use of undue force when connecting the key-parts together. It will be apparent that connection is made between the two members of the key without the use of extraneous fastening means, and that the resiliency inherent in the loops 26 and 2? assures a firm connection between the two members of the key, yet enable them to be separated under application of proper force so that either can be quickly replaced in the event that one becomes worn or broken.

The curvature of the foundation member 25 approximates that of the curvature of the outer face of the brake head and the inner face of the brake shoe, while the curvature of the spring member 24 is such as to convert said member into a spring arm capable of being forced under pressure into a position more closely approximating the foundation member 25. Said foundation member 25 is provided with a stop in the form of a hump or offset 28 formed by bending said member. This hump projects from the concave side of said member and creates a depression or concavity 29 in the convex side thereof.

The lower end of the spring member 2 1 terminates between the ends of the foundation member but by preference I terminate it within the concavity 29, which I have discovered to be desirable in some instances, for the reason that said terminal will ride down an inclined portion of the foundation member when so arranged and assist in more readily reducing the space between the two members while in the act of forcing the key into place between a brake head and a brake shoe.

I also prefer to provide the foundation member at its lower end with an oval shaped stop or protuberance 353 formed on the convex side of the foundation member by forcing the metal of said. member outwardly from the concaved side thereof with a suitably formed tool or the like. Any other shaped stop or protuberance may be employed, but experience has proved the oval shaped stop or protuberance enables the key to be driven out of the brake headmore conveniently without resorting to the use of abar or chisel,

when removing the brake shoe from the brake head.

By reason of the short or spring member 24 being of a greater curvature than the long or foundation member 25, these members are in contact at opposite ends but are spaced apart between their ends, as at 3!.

While I have. referred to the long or foundation member being substantially rigid, such term 1s applied in a comparative sense only, the long or foundation member being formed of somewhat heavier bar or strip material than the short or spring member. Nevertheless, it possesses a certain degree of resiliency, but considerably less than that of the short or spring member formed of bar or strip material somewhat thinner than that of the long or foundation member.

When applying the key in position to secure. or look the brake shoe to the brake head, it is introduced between the two from the upper end. of the brake shoe, the free end of. the long or foundation member 25 being inserted between the lugs 55 of the brake head. The key is then thrust downwardly under hand pressure through the opening 2b in the upper of the intermediate or.

offerslight resistance to the further downward Even after the hump is driven into a position free connector lugs 14, then through the space between the connector lugs l8 of the brake shoe arranged between the inner convex surface of said shoe and the opposing face of the strip or bar l9, and finally through the opening in the lower of the intermediate or connector lugs M of the brake head.

When the hump 2B of member 24 of the key comes in contact with the outer wall of the upperconnecting lug M on the brake head, it may movement of the key, making it necessary to use extra force in moving the key downwardly, and this slight resistance may again be encountered as the hump 28 comes in contact with the outer wall of the lower lug I 4 on said brake head.

When the lower endof the short or spring mem ber 24 of said key comes in contact with the strap or bar IQ of the connector lug on the brake shoe,it will offer sufflcient resistance to the further downward movement of the key to make it necessary to resort to the use of a hammer or other suitable tool to drive the key into position. This will cause said member 24 to flex and assume a curvature more closely approaching that of member 25 while riding downwardly in contact with the strap or bar. The downward movement of the key under force thus exerted will result in the extremity of the key coming in contact with the inner surfaces of the bottom lug 22 on the brake shoe, while the short or spring member 24 of the key extends downwardly through the opening in the lower of the pair of intermediate lugs 24 on-the brake head.

This locking key is so constructed that it will with equal effectiveness secureor lock worn brake shoes to new brake heads; new brake shoes to worn brake heads; worn brake shoes to worn brake heads, or new brake shoes to new brake heads, without possibility of play existing between the two. It will effectively permit the use of brake shoes and brake heads, or either of them, already worn and under present means of connecting brake shoes to brake heads generally considered beyond use, since the inherent resiliency of the short or spring member 24 of the locking key is of such capacity to firmly draw the connector lugs of the brake shoe into the space pro- Vided for them between the connector lugs on the brake head, with absolute assurance of firm contact of the engaging surfaces of said lugs and the elimination of all play.

As is well known, certain types of freight cars are adapted to be completely inverted on supporting platforms when delivering the contents thereof, such as coal and the like, which results in the upper ends of the brake shoes and brake heads being temporarily positioned at the bottom, and in many cases where brake shoes and brake heads are worn, locking keys now employed will, under such conditions, drop out of position, with the result that the brake shoes become disconnected from the brake heads. The loss of brake shoes under such conditions is impossible when using my improved locking key, since the pecularities of the key in addition to the stop hump 28 at or below the extremity of the spring member 24 will come in contact with the lower edge of the lower connector lug M on the brake head, and movement of the key beyond such point cannot take place without the exercise of considerable force applied directly against the lower end of the key, and such force must be sufiicient to cause fiexing of the short or spring member 24 to force the hump or offset 28 upwardly beyond said lug.

of said lug, contact of the opposite faces of the key with opposing surfaces of the brake head and brake shoe will cause the stop or protuberance 30 to engage the inner side of the strap or bar Hi. It will thus be seen that not only is the inherent resiliency of the curved member 24 relied upon to prevent accidental displacement of the locking key, but such displacement is also prevented by the stop hump or offset 28 and the stop or protuberance 30 on the long or foundation' member 25 if either of the members of the key should become worn or broken while the other still proves serviceable.

It is to be understood that under the inherent resiliency of the short or spring member of my improved locking key, wear existing between the brake head and the brake shoe, or wear of the connector lugs will be automatically taken up, and consequently, regardless of the length of the use of the brake shoe and brake head, assurance is had of a tight application of the brake shoe tothe brake headunder all conditions of use, such connection being maintained until either the brake shoe or brake head, or both, are completely worn out. 7

Having thus described my invention, what I claim is:

1. A key for connecting brake shoes to brake heads formed of flexible flat metal strip-material and comprising a long member and a short member detachably connected together at corresponding ends, said members being curved lengthwise and the short member being of greater curvature than the long member and having its extremity in contact with said long member, said long member having a hump on its concaved side and a depression on its convexed side adjacent the extremity of said short member and into which said extremity is adapted to enter.

2 A key for connecting brake shoes to brake heads formed of flexible flat metal strip-material and comprising a long member and a short member, said members being curved lengthwise and the short member being of greater curvature than the long member, said long member having a hump on its concaved side forming a concavity on its convex side between its extremity and the extremity of said short member and said short member terminating at its extremity within said concavity and being adapted to enter the latter on flexing of said short member 3. A key for connecting brake shoes to brake heads, comprising two elongated members provided with loops at corresponding ends, one loop fitting within the other and one of said members being longer than the other, the short member being curved and having its extremity in contact with the long member.

4. A key for connecting brake shoes to brake heads, comprising two flexible elongated members, each having a loop at its upper end, said members being detachably connected together at said ends by said loops arranged one within the other and either being replaceable by a like member upon lateral movement of one with respect to the other, one of said members being longer than the other and the short member being curved and having its extremity in contact with the long member.

5. A key for connecting brake shoes to brake heads, comprising two flexible elongated members connected together, one of said members being longer than the other and said long member having an oval shaped hump adjacent its free end.

6. A key for connecting brake shoes to brake heads, two elongated members provided with loops at corresponding ends, one loop fitting within the other and one of said members being longer than the other, said loops having interlocking means to prevent separation of said members.

7. A key for connecting brake shoes to brake heads, comprising two elongated members provided with loops at corresponding ends, one loop fitting within the other and one of said members being longer than the other, the short member being curved and having its extremity in contact with the long member, one of said loops having a depression and the other having a protuberance fitting into said depression.

8. A key for connecting brake shoes to brake heads, comprising two elongated members provided with loops at corresponding ends, one loop fitting within the other and one of said members being longer than the other, the inner loop having an external protuberance and the outer loop an internal depression to receive said protuberance.

9. A key for connecting brake shoes to brake heads, comprising two flexible elongated curved members provided with loops at corresponding ends, one loop fitting within the other and one of said members being longer than the other, the inner loop having an external protuberance and the outer loop an internal depression to receive said protuberance.

WILLIAM J. MACK. 

